Practical automatic sod harvesters, in which sod is harvested from the ground and stacked on a pallet, have existed for about 40 years. Originally, such harvesters formed the cut sod into rolls which were stacked on pallets, moved to a site where sod was needed, and then laid. However, there are various disadvantages associated with rolling the sod, and therefore an alternative method of sod handling became popular, in which the sod was simply cut into slabs (i.e. flat lengths of sod) which were stacked on pallets and handled in that form. Leaving the cut sod in flat slabs tends to impose less severe mechanical stresses on the sod, and in addition more sod can be stored in a smaller space. However, lifting the slabs automatically has proven difficult.
Various methods have been suggested for lifting sod slabs and for moving the slabs once lifted. One such method, suggested by the present applicants, was to pierce the sod slabs with hooks which could then be used to lift and move the slabs. However, the hooks, in use, in some cases protrude below the bottom surface of the sod slab and can in some situations create awkwardness in handling the slab. In addition, release of the sod slab from the hooks can sometimes be difficult.
In addition, once the sod slabs are stacked on a pallet and have been moved to a worksite where the sod is to be laid, it may not always be practical to employ hooks to lift the sod slabs in order to lay them. Therefore, to date, the sod slabs have usually been handled manually, which is a labor intensive and costly job.